Block Diagram
CAN abbreviations
| E55_L | Side turn signal, left | E69_R | Front fog lamp, right |
|---|---|---|---|
| E55_R | Side turn signal, right | E121_L | Headlamp, front left |
| E69_L | Front fog lamp, left | E121_R | Headlamp, front right |
Block Diagram (Continued)
| 31 | Ground (terminal 31) | S255 | Switch, residual washer fluid |
|---|---|---|---|
| B11 | Horn | Y105 | Washer pump, rear |
| M17 | Windscreen wiper motor | Y106 | Washer pump, front |
| S32 | Reversing lamp switch |
Function Table
Wiring harness plug X1 = 22-pin
Wiring harness plug X2 = 50-pin
Wiring harness plug X3 = 30-pin
| Terminal | Description | Source | Destination |
|---|---|---|---|
| X1-1 X1-2 X2-44 LSCAN | Automatic transmission, gear information (reverse gear engaged) | CIM | UEC |
| X1-1 X1-2 X2-44 LSCAN | Ignition lock information | CIM | UEC |
| X1-1 X1-2 X2-44 LSCAN | Position of horn switch is transmitted for actuation of the horn | CIM | UEC |
| X1-1 X1-2 X2-44 LSCAN | Light switch functions Turn signal activation | BCM | UEC |
| X1-1 X1-2 X2-44 LSCAN | Activation of safety functions in the event of a crash (turn signal lamp actuation) | BCM | UEC |
| X1-1 X1-2 X2-44 LSCAN | Windscreen washer system switch active Rear screen washer system switch active Windscreen wiper switch active Rear screen wiper switch active Wiper interval value (sensitivity, rain sensor) | CIM | UEC |
| X1-1 X1-2 X2-44 LSCAN | Windscreen rain sensor request | REC | UEC |
| X1-1 X1-2 X2-44 LSCAN | Rear screen wiper activation request Washer fluid level low Windscreen wiper park position switch (with rain sensor) | UEC | REC |
| X1-1 X1-2 X2-44 LSCAN | High beam switch active Headlamp flasher switch active Turns signal switch (parking light with ignition OFF), activation | CIM | UEC |
| X1-1 X1-2 X2-44 LSCAN | Current driver's door status is transmitted | BCM (ATWS) DDM | UEC |
| X1-1 X1-2 X2-44 LSCAN | Low beam switch activated Front fog lamp switch active Parking light switch active | BCM | UEC |
| X1-1 X1-2 X2-44 LSCAN | Activate turn signal / hazard warning lights, front right Activate turn signal / hazard warning lights, front left Turn signal / hazard warning lights, period duration Turn signal / hazard warning lights, make-to-break ratio | BCM | UEC |
| X1-1 X1-2 X2-44 LSCAN | Warning/message signals for CIM loudspeaker | UEC | CIM |
| X1-1 X1-2 X2-44 LSCAN | Turn signal lamp bulb, front left/left side turn signal defective Turn signal lamp bulb, front right/right side turn signal defective Fog lamp bulb, front left defective Fog lamp bulb, front right defective High beam bulb, left defective High beam bulb, right defective Low beam bulb, left defective Low beam bulb, right defective Parking light bulb, left defective Parking light bulb, right defective | UEC | BCM DIS IPC |
| X1-1 X1-2 X2-44 LSCAN | High beam on Front fog lamp on Left parking light on Right parking light on Low beam on Manual transmission reverse gear active | UEC | IPC CIM DIS PAS REC |
| X1-3 | Ignition ON (terminal 15) | CIM | UEC |
| X1-5 | Windscreen wiper input "High speed" – redundant wiper actuation | CIM | UEC |
| X1-6 | Synchronisation signal between front and rear turn signal lamps | BCM | UEC |
| X2-1 | Actuation for parking light, front right | UEC | E121_R |
| X2-2 | Actuation for turn signal lamp, front right | UEC | E121_R |
| X2-3 | Actuation for turn signal lamp, front left | UEC | E121_L |
| X2-4 | Actuation for side turn signal lamp, left | UEC | E55_L |
| X2-8 | Actuation for parking light, front left | UEC | E121_L |
| X2-9 | Actuation for side turn signal lamp, right | UEC | E55_R |
| X2-10 | Actuation for fog lamp, front right | UEC | E69_R |
| X2-11 | Windscreen wiper park position | UEC | M17 |
| X2-14 | Washer fluid level | S255 | UEC |
| X2-15 | Actuation for low beam, right | UEC | E121_R |
| X2-16 | Actuation for high beam, left | UEC | E121_L |
| X2-18 | Ground for UEC | Ground | UEC |
| X2-26 | Actuation for screen washer pump, front | UEC | Y106 |
| X2-29 | Actuation for high beam, right | UEC | E121_R |
| X2-30 | Actuation for windscreen wiper, speed 2 | UEC | M17 |
| X2-31 | Ground for UEC | Ground | UEC |
| X2-33 | Actuation for low beam, left | UEC | E121_L |
| X2-34 | Horn actuation | UEC | B11 |
| X2-35 | Actuation for windscreen wiper, speed 1 | UEC | M17 |
| X2-36 | Actuation for headlamp washer pump | UEC | Y106 |
| X2-37 | Actuation for fog lamp, front left | UEC | E69_L |
| X2-43 | Actuation for screen washer pump, rear | UEC | Y105 |
| X3-5 | Reversing lamp switch, manual transmission | S32 | UEC |
Functional Description
The engine compartment electronics module (UEC) is a control unit for electronic actuation of the front lighting. It is responsible for fault detection of the lamps installed in the front of the vehicle. A further main function of the UEC is actuation of the relay installed in the UEC. In addition, the UEC includes the fuses (terminals 15 and 30) for all the control units installed in the front section of the vehicle. The UEC receives most of the control data which influences lighting, screen-wiper functions and the actuation of various relays (e.g. ignition ON (terminal 15) and horn) from the low-speed CAN bus.
The UEC is responsible for the following functions:
- Front exterior lighting
- Windscreen wipers
- Screen washer system
- Headlamp washer system
- Rear screen washer system
- Washer fluid level
- Horn
Voltage Management Function
In the Vectra-C, the UEC is responsible for the complete voltage supply (terminal 30). The REC, IPBEC, ABS and fan motors are supplied with voltage from the main fuses of the UEC. The fuses to protect all the control units are located in the UEC, REC and IPBEC. A directly wired terminal 15 signal, as well as the terminal 15 status are transmitted to the UEC from the CIM via LSCAN.
Function of Screen Wipers, Screen Washer System, Headlamp Washer System
The UEC is responsible for the following wiper functions:
- Windscreen wipers
- Windscreen washer system
- Headlamp washer system
- Rear screen washer system
- Washer fluid level
See also Chapter: Wash/wipe system – function
Fault Remedy
In the case of a defective CIM or of faulty CAN bus communication, the wiper function is ensured via a directly wired line from the CIM to the UEC. In this case, the wiper relay for fast wiper speed is activated directly via this line. In the event of faulty CAN communication, the screen washer function is no longer effective.
Horn Function
The horn switch status registered by the CIM is transmitted to the UEC via the LSCAN. The UEC actuates the horn relay when it receives the CAN message "Horn switch actuated".
See also Chapter: Horn – function
Function of Reversing Lamp Switch (Manual Transmission)
The UEC detects the position of the reversing lamp switch This information is transmitted to other control units by the UEC via CAN.
Function of Exterior Lighting, Front
The UEC is responsible for the actuation and failure monitoring of the following lighting functions:
- Parking lights
- Low beam (halogen or xenon)
- High beam
- Front and rear side turn signal lamps
- Additional/auxiliary lighting functions
See also Chapter: Exterior lighting – function